Chain stitch zigzag sewing machine for ornamental seams



April 26, 1938. EBE'RTV 11 15,488

CHAIN STITCH ZIGZAG SEWING MACHINE FOR ORNAMENTAL SEAMS Filed Jan. 14, 1936 4 Sheets-Sheet l INVENTOR FRVFZ EBERT ATTORNEY April 26, 1938. EBERT 2,115,488

CHAIN STITCH ZIGZAG SEWING MACHINE F OR ORNAMENTAL SEAMS FRwz EBERT ATTOR' [Y April 26, 1.938. EBERT 2,115,488

CHAIN STITCH ZIGZAG SEWING MACHINE FOR ORNAMENTAL SEAMS Filed Jan. 14, 1936 4 Sheets-Sheet 3 \NVENTOR 42 FRITZ [BERT Br ATTORNEY April 26, 1938. v F. EBERT 2,115,488

CHAIN STITCH ZIGZAG SEWING MACHINE FOR ORNAMEN'I'AL SEAMS Filed Jan. 14, 1936 4 Sheets-Sheet 4 f i I' mvcmmR FRITZ .EBERT By ciTj omqfl .iinemed' Apr. 26, was

UN rso j STATE So PATENT OFFICE.

cmmv s'rrrcn ZIGZAG- snwnro mounts FOR-OBNAMENTAL SEAMS.

I rits Ebert, -Oberndori-on-the-Neckar, Germany, assiznor to Mauser-Works A. G., Oberndort-onthe-Nectar, Germany,

v of Germany a' joint stock company Application 'Jauuary. 14, 1938, semi a. 59,144

In Germany January 16, 1935 1 Claim. (Ci. 1125159} Hitherto known chain stitch zigzagsewing machines are notadapted for high speeds for the reason that roller cams are used for the sup-- plementary drive of the looper and for the con- 5 trol of theneedle shank frame. In these known machines the mechanism comprises either .two small roller cams or one large roller ca'nr'and double transmission, a complicated inner system of gearing being used for the one transmission.

Power transmission by roller cams is not suitable for high speeds since very great axial pressures take place therein. The oscillating power, transmission levers are greatly stressed, so that under certain circumstances even breakage-s o! the lever may occur. Furthermore, the roller.

cam drive increases the cost oi production or V the machines considerably, since either double wheel transmissions or two suchcams are neces- V sary. 30 Finally, owing to'the roller cams, the cleartime space over the table plate between the sewing mechanism and the foot of the casing isconsiderably restricted, which' -a'gain causes a reduced output oi work. 7 'j "The present invention has for its object a sewing machine which runs perfectly at an extremely high speed-yet having none oi the defects of the known machine. These advantages are in. the main attained by the use instead ot a roller cam-of a flat or face cam,'..that is, a level cam groove arra'ngeclin a horizontal plane under the table plate of the machine vwhich is directly driven fromthe main spindle by a pair of helical wheels.

.By choosing a. it is possible t5 arrangethis, togetherwith the entire drive, uridrneathjhe-table plate, -where-, by as compared with hitherto known sewing machines of this nature, the,whole,space above the 40 table plate betweenthe foot oithe casing and the sewing mechanism can be utilized for the passage of the material, which is furthermore en- .7

tirely protected ,Irbm being soiled by oil.

{ is jflttedon a vertical spindle, which produces The guide roller or a double armed lever whic both the supplementary movement of the looper,

and also the oscillating movement a! the needle.

shank frame, engages in the cam groove of the face cam. .The forward arm of this double armeddriving lever. produces the supplementary looper 7 movement, whilst the needle shank frame is us ciilated by another lever'armntted on the axis of oscillation thereof. The whole extremely sta-' bledriving assresat'e thus consists of only the face cam "as the driving means,

" fully explained by face cam'and the double levertogether with its vertical spindle.- r

In order that the needle may always penetrate. correctly, there are provided two possible adjust ments for it. -Thus, an adjustment of the main 5 positionof the needle is possible and an adjustment oi the lateral stops. The former is efl ected by rotating the connecting rod transmitting the driving movement on to the needle shank iiarme. For this purpose, the connecting rod is. provided ill at its ends with right and left-handed threads, by means of which it is screwedtinto its end pieces whereby the length of the transmission means, as also thereby the main position of the needle shank frame is altered. The lateral'dee W ilection is altered by varying the transmission ratio, the point of application of the connecting rod on to'its driving lever being shifted with respect to the axis of oscillation. In this way, var

ious types of stitches may be obtained on the m same machine. V

In order to prevent entirely an oscillation of the needle shank frame and to be able tc'produce a straight seam line, the setting device of the driving lever oi the connecting rod is so made 25 that its pointof attachment can be shifted to the centre of the axis of oscillation of its driving lever. Instead of the zigzag seam, a straight seam is then produced. r Furthermore, various kinds of sewing can be 39 produced without altering the transmission by provision being madethat, in addition .to, the Y interchangeability of the pairs of helical wheels,

- the face cam itself can be exchanged. 1 r In order to compensate for small difierenc'es in the distance between the spindles when, choosing different transmissions, the-large helical wheel of the face cam drive is fitted on an eccentric stud which, in known manner, isso rotated that the helical wheels used always come into correct engagement.

J-inally, provision is made-in order to exchange simultaneously in an advantageous manner all the stitch-forming tongues of theneedle plate, 45

such'as for example when thenumb'er of the tonguesistobechanged- K The object of the present inventionis more way of example on the annexeddrawings '7 7.50

Fig. 1 is a perspective view of the machine according tothe invention, 1 v

Pig. 2 is a partsectional front elevation of the manclgzire showingsome oi the essential parts,

is a verticai'sechon perpendicular to the 55 main spindle of the sewing machine through the axis of the face cam.

Fig. 4 is a plan of the face cam drive.

Fig. 5 is a vertical section of the bearing of an angle lever for the supplementary looper drive.

Figs. 6, 'I and 8 are respectively longitudinal elevation, plan and end view of the needle shank drive.

Fig. 9 shows a'number of ornamental stitch work designs which may be produced with the same transmission simply by interchanging the face cam.

Figs. 10, 11 and 12 show the needle plate in plan and side section with two different tongue plates.

The sewing machine or respectively its various members are, as usual, driven by the main spindle l running horizontally. The drive of the needle 2 and the main drive of the looper 3 are, as usual, and are not described. The movements of needle -2 and looper 3 are also usual, that is, the needle 2 is oscillated laterally and the looper 3 obtains in addition to its normal movement, a supplementary movement in order to give it a correct movement with respect to the needle 2.

For oscillating the needle shank frame 4 carrying the needle 2, about the vertical axle 5 and for controlling the looper 3 or respectively its supplementary movement, according to the present invention there is provided a face cam 6, that is, a cam groove which with its perpendicular axle I, that is, with its plane in the horizontal direction, is arranged under the table plate 8. It is driven by the main spindle l by means of the helical wheels 9 and i and controls a double armed lever II which is fitted on a vertical oscillating axle l3 carried on the housing l2 of the sewing machine.

The supplementary movement is transmitted to the looper 3 from the forwardly located arm of the double armed lever II by a link piece i engaging on a ball pin l4 thereof and an angle or elbow lever I6 which is fitted on a stud I! rotatably carried in the sewing machine housing l2 (Fig. 5) and by means of a link piece l8 oscillates an elbow lever 2| carried on the arm IQ of the needle drive lever 2|]. This angle lever drives the looper 3 by means of the connecting rod 22 in the usual way, the necessary supplementary movement being imparted thereto by the face earn 6. The needle shank frame 4 is oscillated by the rocking of the vertical spindle l3. For this purpose, there is fitted at the top of the spindle l3 an arm 23 which, by means of a connecting rod 24 engages a projection 25 extending out towards the rear, which oscillates the needle shank frame 4, (Figs. 2, 3 and 4).

In order to be able to vary the type of stitch,-

the connecting rod 24 is provided at its ends with right and left-handed threads, so that by rotating it the main position of the needle 2 is varied. Furthermore, the connecting stud 28 of the rod 24 on the arm 23 can be shifted with respect to the axis of rotation :3. For this purpose, there is provided in the arm 23 a radial groove 21 in which the stud 28 may be adjusted and fixed, so that the transmission ratio may be varied.

The face cam 6, the helical wheel I0 fitted on its spindle I, as also the helical wheel 9 on the main spindle I, are interchangeable in order to be able to carry out different types of stitching, as can be seen for example in Fig. 9, the different arrangements having all been made with the same pair of wheels but with different face cams.

In order to bring the helical Wheels 9 and it after their exchange, into correct engagement, the spindle I is made as an eccentricv stud. By rotating this, the helical wheel I0 is brought into engagement with the helical wheel 9. For this purpose, the eccentric axle I in the bearing centre 28 of the face cam housing 29 is arranged to be rotatable and is fixed in the adjusted position by two screws 30.

In order to attain silent runningof the machine, the helical wheel I0 is provided with a special toothed rim, of material which works noiselessly, for example, compressed fabric. This toothed rim is fixed on the boss 3| of the helical wheel in by screws 32. On this boss 3| there is also fitted the face cam 6 which is fixed thereon by screws 33 and can consequently be easily exchanged in order to be ableto use different kinds of cams 6 with the same transmission. By means of a cover disc 34 and screw 35, the inserted face cam 6 is prevented from rising upward.

The face cam 5 or its cam groove controls, as usual, the double armed lever H by means of a roller 36 running in the groove 6 which roller is carried on the rear arm of the double armed lever H by means of a pin 31. Thispin 31 can be adjusted on the arm by which it is axially carried, in any suitable manner in order to be able to adjust the slightly conical roller 35 in the corresponding conical groove of the face cam 6 to allow for wear.

The tongues 38 of the needle plate 39 are interchangeable and the arrangement is so contrived= that tongues 38 of different number can be simultaneously inserted by simple exchange. For this purpose, all the tongues 38 are on a common plate 40 which, by means of a screw 4|, is fixed in a recess 42 of the needle plate 39 adapted thereto. The recess 42 is, as shown by Figs. and 11, made wide enough to accommodate the widest plate 40, that is, the one with the most tongues 38. In order to fill up the space of the recess 42 when there are fewer tongues 38 than required for the space intended for the largest number of tongues, there is provided on the tongue plate 40 a projection 43 covering the gap which would otherwise be left.

I claim:

A zigzag chain stitch sewing machine for producing ornamental seams, comprising a needle shank frame, a table frame, a face cam horizontally provided in the machine under the table frame, a double-armed lever having one end thereof cooperating with the face cam, means for driving said face cam, and a second lever for driving a looper mechanism, said face cam oscillating the needle shank frame by means of the double armed lever and the looper mechanism in cooperation with the second lever.

- FRITZ EBERT. 

